Etymonline
Word origins and English word etymologies
Origins and histories of English words from the Online Etymology Dictionary.
Your information
English word to look up, such as salary.
Example results
Word origins
About the Etymonline tool
Etymonline, also called Online Etymology Dictionary, provides word origin entries by part of speech; it needs an English word as input.
Built from etymonline.com. Last checked Sep 29, 2026.
Actions
Get word origin
1 creditGet the origin of an English word, with separate entries by part of speech, the first date mentioned, and linked related words. Dates may be absent for some entries.
What you provide
| Field | Type | Required | Description |
|---|---|---|---|
Wordword | Text | Required | English word to look up, such as salary.Example: Serendipity |
What you get
| Field | Type | Description |
|---|---|---|
Entriesentries | List | Origin entries for the requested word, one per listed part of speech. |
Headingentries[].heading | Text | Entry heading as printed on the page.Example: serendipity (n.) |
Entry Linkentries[].entry_link | Text | Link to this entry on Etymonline.Example: https://www.etymonline.com/word/serendipity |
Earliest Dateentries[].earliest_date | Text | First date mentioned in the origin explanation, as printed.Example: before 20c. |
Related Entriesentries[].related_entries | List | Words cross-referenced from this origin explanation. |
Origin Explanationentries[].origin_explanation | Text | Full origin explanation in plain text.Example: "to pay a regular salary to," late 15c. (Caxton), from salary (n.). Related… |
Example result
For Word: Serendipity
{
"entries": [
{
"heading": "serendipity (n.)",
"entry_link": "https://www.etymonline.com/word/serendipity",
"earliest_date": "before 20c.",
"related_entries": [
"Sri Lanka"
],
"origin_explanation": "\"faculty of making happy and unexpected discoveries,\" a rare word before 20c., coined by Horace Walpole in a letter to Horace Mann that is dated Jan. 28, 1754, but which apparently was not published u…"
}
]
}For developers
Call it from your code with one request. Change the values in input to run it on new data. To get an API key, open Developers at the bottom of Studio, turn on Developer mode and go to API keys.
curl 'https://api.fous.com/v1/query' \
--fail-with-body --silent --show-error --max-time 180 \
-H "Authorization: Bearer YOUR_API_KEY" \
-H 'Content-Type: application/json' \
--data-raw '{
"api": "@etymonline",
"visibility": "public",
"operation": "get_word_origin",
"version": 1,
"input": {
"word": "serendipity"
},
"response": {
"format": "json"
}
}'What you can do with it
- Trace the origins of English words
- Review the first date mentioned for a word
- Explore related words cross-referenced in an origin entry
Questions about Etymonline
Can I run it with my own inputs?
Yes. Change the inputs in Studio and press Run, or send new inputs from your code, or ask a connected AI assistant.
Can I call this Etymonline tool as an API?
Yes. Send a POST request to /v1/query with your Fous API key and the inputs, and get JSON back.
How much does it cost?
Each completed run costs 1 credit. Failed runs without a completed receipt are free; completed work can remain charged if delivery is interrupted. With pay as you go, a credit costs 1¢. Monthly plans cost less per credit.
Do I need a Etymonline account?
No. You only need a Fous account.
How current is the data?
Fous gets the data from etymonline.com when you run it. Some results are reused for up to 24 hours, and results that use your account or key are never reused. It was last verified on Sep 29, 2026.
Where does an English word come from?
Use Get word origin with an English word to retrieve its origin explanation.
When is a word first mentioned?
Get word origin returns the first date mentioned in each origin entry, when available.
Which words are related to an origin entry?
Get word origin returns words cross-referenced in the origin explanation.